无积分误差的双相关频差补偿信道测试方法

Channel sounding without integral error by dual-correlation to compensate frequency difference between transmitter and receiver

针对未来无人机、航天、地铁等无法同步的无线信道测试工程中,收发端无法同步的问题,提出了一种无积分误差的双相关频差补偿信道测试方法,预先设置频差,在训练阶段存储频差参数,在测试后对随机序列以及频差实施相关运算,补偿收发端之间的频差影响。提出了数值预置、直连获取、信道获取等3种频差获取方案,适用于不同的工作环境。理论分析与实验表明所提方法在任意频差下,均能有确定性输出,且随着收发间频差的增加,最终输出可收敛于同步情况下输出幅度的一半,解决了特殊环境下信道检测的难题。

This letter presents a wireless channel sounding method for unmanned aerial vehicles(UAV),aerospace,metro and other scenarios,when the synchronization between the transmitter and receiver is difficult.The principle of this method is setting the frequency difference between the transmitter and receiver in advance,detecting the frequency difference in the training step,and performing the double correlation operation on the random sequence and frequency difference in the working step.This method eliminates the influence of the frequency difference between the transmitter and receiver,and achieves the channel impulse response(CIR)without integral error.In this letter,three kinds of differential frequency acquisition schemes for different working environments are proposed,which are numerical preset,direct connection acquisition and the wireless channel acquisition.Theoretical analysis and experimental results demonstrate that this method has the advantage of definite output under any frequency difference.With the increase of frequency difference,the final output converges to half of the synchronous output amplitude,which provides a solution for the channel sounding in some special environments.